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Biomedical subjects

H Nishimura

Publications and source records attributed to H Nishimura.

At least 703 records · Page 39Linked to original sources
PubMed1987

[Second look operations in ovarian cancer--a clinical study on the detection of recurrent tumors and the judgment on termination of treatment in 84 cases].

Various investigations were conducted on 84 patients undergoing a second look operation (S.L.O.) intended to detect any recurrent tumors and determine the timing of the cessation of therapy. The following conclusions were obtained: Tumors were found in 18 patients (21.4%) whose preoperative diagnosis was neither subjectively nor objectively abnormal. Patients who received S.L.O. had a considerably better 5 year survival rate than the control group. S.L.O. can safely be omitted only in patients with Stage I border line ovarian tumors. S.L.O. is essential in cases where basic surgical procedures were not carried out during the initial operation. No occlusion could be reached as to the best time to perform S.L.O. In almost all of the patients who died, the site of recurrence was somewhere outside the abdominal cavity, but no recurrent tumors had been found during S.L.O. S.L.O. is still a more efficient follow-up method than CA125, TPA or IAP tumor markers, although the preoperative results of these tests reflected the laparotomy findings relatively well.

Adult↗
PubMed1987

[Chemotherapy and surgical procedure in the management of ovarian malignancies. Evaluation of second look operations].

Recently, the second-look operation (SLO) has become an established part of the protocol of many centers for patients with ovarian malignancies who have received chemotherapy. This surgical procedure for ovarian cancer can be used for various purposes, therapeutic or diagnostic. The first main indication of SLO is resection of a residual tumor by as great an extent as possible following chemotherapy. In our experience, the prognosis was more favorable in patients in whom the residual tumor had been reduced to 2 cm or less upon SLO than in those in which the residual tumor was larger than 2 cm. In addition, maximum possible reduction of the advanced disease at the time of initial operation serves to enhance the effectiveness of chemotherapy. The second main indication is evaluation of the disease with the intent of stopping chemotherapy and assessing any signs of early recurrence. In our experience, approximately 50% of patients who had cancer at the time of SLO were clinically free of the disease prior to the operation. Therefore, we think that effective combination of chemotherapy and SLO are the key to improving patients, prognoses.

Antineoplastic Agents↗
PubMed1986

Effect of lipophilic cations on thiamine transport system in isolated rat hepatocytes.

The effect of lipophilic cations such as triphenylmethylphosphonium, tetraphenylphosphonium and tetraphenylarsonium in addition to dibenzyldimethylammonium on thiamine transport in isolated rat hepatocytes was studied. Lipophilic cations at the concentration 10 microM almost completely inhibited thiamine uptake. Kinetic studies showed that these compounds were competitive inhibitors with a very high affinity. These results suggest that lipophilic cations in addition to quaternary ammonium compounds also share a common binding site for thiamine in isolated rat hepatocytes.

Animals↗
PubMed1986

HTLV-I seroprevalence in patients with malignancy.

Since many malignancies often occur in patients with smoldering type adult T-cell leukemia (ATL) (5 of 18 cases in this report), the relationship between HTLV-I (human T-cell leukemia virus type I) infection, which is closely associated with ATL, with other malignancies in an HTLV-I endemic area was examined. Among the 394 patients with malignancies and who had not had blood cell transfusions, 61 (15.5%) tested positive for HTLV-I antibody. The prevalence was significantly higher in males older than age 40 years and females of all ages compared to age- and sex-matched healthy individuals. The overall seroprevalence (26.1%) in 291 patients with malignancies and who had had blood cell transfusions was higher than that of those who had not had blood transfusions. There was no significant correlation between the site of malignancy and antibody prevalence. These results suggest the possibility that development of malignancy may contribute to expression of latent HTLV-I infection and that HTLV-I infection may contribute to the risk of other malignancies.

Adolescent↗
PubMed1986

Thyrotropin-releasing hormone-induced changes in electroencephalographic and vagal activity in the cross-circulated brain of the rat.

The effects of centrally administered thyrotropin-releasing hormone (TRH) on vagal efferent and cortical electroencephalographic (EEG) activity were assessed in rat brains which were functionally isolated from the body trunk and maintained via cross-circulation. Upon withdrawal of inputs from the trunk, cervical vagal activity was markedly attenuated. The decreased activity was partially restored by TRH with a latent period of a few minutes. On the other hand, TRH immediately but transiently augmented the fast waves of the EEG. The change in brain activity produced by TRH appears to simulate the state which makes possible the generation of vagal efferent activity even though inputs from the body trunk are withdrawn.

Animals↗
PubMed1986

Effect of tunicamycin on thiamine transport in Saccharomyces cerevisiae.

The activity of thiamine transport in Saccharomyces cerevisiae was decreased by the treatment with tunicamycin without affecting the growth of yeast cells. Although the total activity of a soluble thiamine-binding protein in yeast periplasm, which is known to be a glycoprotein, was decreased by tunicamycin treatment, the activity of thiamine uptake by yeast protoplasts was inhibited as much as by whole cells. Furthermore, tunicamycin decreased the activity of the membrane-bound thiamine-binding protein in a dose dependent way and in parallel with the thiamine transport activity. These findings suggested that the membrane-bound thiamine-binding protein is a glycoprotein which plays a functional role in thiamine transport in S. cerevisiae.

Acid Phosphatase↗
PubMed1986

Thiamine-binding activity of Saccharomyces cerevisiae plasma membrane.

The specific binding activity to [14C]thiamine was found to be located in hte plasma membrane of Saccharomyces cerevisiae. The activity was inhibited by several thiamine analogs and it was hardly detectable in the plasma membrane from a thiamine transport mutant of Saccharomyces cerevisiae. Some properties of the thiamine-binding activity of yeast plasma membrane are discussed in connection with those of the thiamine transport system.

Biological Transport↗
PubMed1986

Antigenic variation among human strains of influenza C virus detected with monoclonal antibodies to gp88 glycoprotein.

Antigenic variation among influenza C virus strains was investigated with monoclonal antibodies against gp88 glycoprotein. Seven monoclonal antibodies obtained were tentatively classified into two groups, A and B. The group A antibodies had hemagglutination inhibition (HI), hemolysis inhibition and neutralization activities whereas the group B antibodies possessed none of them. A comparison of antigenicity among 15 human strains with these antibodies in radioimmunoprecipitation and HI tests showed that the regions recognized by the group A antibodies undergo considerable changes, whereas those by group B are conserved among the strains.

Animals↗
PubMed1986

Ampicillin concentrations in human serum and periodontal membrane following a single oral administration of bacampicillin.

Ampicillin concentrations in human serum and periodontal membrane after a single oral administration of bacampicillin (500 mg) were assayed by the agar diffusion (paper disc) method. The peak times of serum and periodontal membrane were nearly identical, being approx. 90 min after administration. The peak concentrations of serum and periodontal membrane were 12.81 micrograms/ml and 6.97 micrograms/g, respectively. The concentration ratio of periodontal membrane to serum at the peak time was 0.56.

Adult↗
PubMed1986

Incorporation of inositol in the cochlear tissues as determined by autoradiography.

The sites of incorporation of [3H]inositol perfused perilymphatically in the guinea pig cochlea were localized autoradiographically. In the organ of Corti, active incorporation occurred in the synapses, nerve fibers, pillars and nuclei of various cells. Both hair cells and supporting cells moderately incorporated inositol. In the lateral wall of the cochlear duct marked incorporation was observed in the epithelia of the vascular stria and spiral prominence. The possible involvement of inositol phospholipids in auditory transduction at the organ of Corti and in ionic transport in the lateral wall of the cochlea is briefly discussed.

Animals↗
PubMed1986

Some properties of a Saccharomyces cerevisiae mutant resistant to 2-amino-4-methyl-5-beta-hydroxyethylthiazole.

A mutant of Saccharomyces cerevisiae highly resistant to 2-amino-4-methyl-5-beta-hydroxyethylthiazole (2-aminohydroxyethylthiazole), an antimetabolite of 4-methyl-5-beta-hydroxyethylthiazole (hydroxyethylthiazole), has been isolated. Its resistance to 2-aminohydroxyethylthiazole was about 10(4) times that of the sensitive parent strain. The amount of thiamin synthesized in the cells of the resistant strain grown in minimal medium was less than half of that of the sensitive strain. The ability to synthesize thiamin from 2-methyl-4-amino-5-hydroxymethylpyrimidine (hydroxymethylpyrimidine) and hydroxyethylthiazole in the resistant strain was low compared with that of the sensitive strain. These results were found to be due to a deficiency of hydroxyethylthiazole kinase in the resistant strain: in sonic extracts of cells the enzyme activity was only 0.67% of that of the sensitive strain. Although the cells of the sensitive strain could accumulate exogenous hydroxyethylthiazole in the form of hydroxyethylthiazole monophosphate, no significant uptake of hydroxyethylthiazole by the cells of the resistant strain was observed. The possibilities that 2-aminohydroxyethylthiazole monophosphate may be the actual inhibitor of the growth of Saccharomyces cerevisiae, and that hydroxyethylthiazole may not be involved in the pathway of de novo synthesis of thiamin via hydroxyethylthiazole monophosphate, are discussed.

Drug Resistance, Microbial↗
PubMed1986

Diluting segment in avian kidney. I. Characterization of transepithelial voltages.

Renal tubules from the Japanese quail, Coturnix coturnix, were perfused in vitro to characterize the transepithelial voltage (Vt). The thick limb (TL) of the mammalian-type (MT) nephron showed Vt positive in the lumen (+9.1 +/- 0.7 mV, n = 35). The Vt decreased with increases in hydrostatic perfusion pressure. Furosemide (lumen), Na cyanide (bath), and ouabain (bath) reversibly reduced Vt. Removal of Cl or Na from the perfusate and the bath decreased Vt of the TL from +10.3 +/- 3.0 to -0.3 +/- 0.3 (n = 5) and from +7.4 +/- 1.5 to +1.2 +/- 0.2 mV (n = 8), respectively. The distal tubule of the reptilian-type (RT) nephron showed two types of Vt: a lumen-negative Vt in the late segment and a lumen-positive Vt in the early segment that is in close contact with the parent glomerulus. Both voltages were reversibly reduced by ouabain and Na cyanide. These results suggest that in quail the TL of the MT nephron resembles the thick ascending limb of the mammalian kidney with both Na and Cl required for generation of luminal positivity and the distal tubule of the RT nephron appears functionally heterogeneous.

Animals↗
PubMed1986

Diluting segment in avian kidney. II. Water and chloride transport.

The mammalian-type nephrons of avian kidneys contain a Henle's loop that runs parallel to the collecting ducts and the vasa recta. Thus we examined whether the thick ascending limb (TAL) of Henle's loop of the avian kidney acts as a diluting segment by measuring water and Cl transport in the isolated and perfused TAL of the quail, Coturnix coturnix. The TAL showed a lumen-positive transepithelial voltage (Vt) (+9.4 +/- 0.4 mV, n = 28). Net water flux (Jv) was nearly zero when the TAL was perfused and bathed with isosmotic solution. When the osmotic gradient was imposed, Jv increased only slightly, and thus the osmotic water permeability (Lp) was low. Arginine vasotocin (AVT) added to the hyperosmotic bath did not alter either Jv, Lp, or Vt. Cl efflux (lumen to bath, 370.4 +/- 27.7 peq X mm-1 X min-1) was higher than Cl influx (bath to lumen, 98.6 +/- 14.3 peq X mm-1 X min-1) when measured in the different tubules. AVT showed no effect on Cl efflux. These results indicate that in the TAL of the quail osmotic water permeability is low while net Cl reabsorption is present, suggesting that the TAL functions as a diluting segment.

Animals↗